谁帮忙解个不等式:t的3次方减去3t减去2大于0

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谁帮忙解个不等式:t的3次方减去3t减去2大于0

谁帮忙解个不等式:t的3次方减去3t减去2大于0
谁帮忙解个不等式:t的3次方减去3t减去2大于0

谁帮忙解个不等式:t的3次方减去3t减去2大于0
t^3-3t-2>0
(t^3-t)-(2t+2)>0
t(t^2-1)-2(t+1)>0
t(t+1)(t-1)-2(t+1)>0
(t+1)(t^2-t-2)>0
(t+1)(t-2)(t+1)>0
(t+1)^2*(t-2)>0
因为:(t+1)^2>=0
所以:t-2>0
即:t>2

t^3-3t-2=(t-2)(t+1)^2>0
=> t≠-1 且 t-2>0
=> t>2

t^3-3t-2>0
t^3-4t+t-2>0
t(t^2-4)+(t-2)>0
t(t+2)(t-2))+(t-2)>0
(t-2)(t^2+2t+1)>0
(t-2)(t+1)^2>0
(t+1)^2≥0且当t=-1时才=0
所以:本题(t-2)>0且t=-1
答案:t>2

先解对应方程t^3-3t-2=0
t^3-3t-2=t^3-t-2t-2=t(t+1)(t-1)-2(t+1)
=(t+1)(t^2-t-2)=(t+1)^2*(t-2)
因为(t+1)^2>=0,要是原式大于0,则只需t>2且t!=-1
即不等式解为t>2

t3-3t-2>0
t3-t-2t-2>0
(t+1)(t2-t-2)>0
(t+1)(t+1)(t-2)>0
t>2
不会用上标,将就着看吧。